<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 980px;
            height: 400px;
            border: 1px solid red;
            /* 默认全平铺 */
            background-image: url("./images/bg.png");
        }
        .dv1 {
            /* 水平平铺 */
            background-repeat: repeat-x;
        }
        .dv2 {
            /* 垂直平铺 */
            background-repeat: repeat-y;
        }
        .dv3 {
            /* 不平铺 */
            background-repeat: no-repeat;
        }
    </style>
</head>
<body>
<div class="dv1"></div>
<div class="dv2"></div>
<div class="dv3"></div>
</body>
</html>